Support apparatus for underwater power generator and method for deployment

ABSTRACT

A support apparatus for support of an underwater power generator is described. The underwater power generator has a power generating portion and the support apparatus includes: a stand adapted for supporting the power generating portion, and comprises a stabiliser including one or more stabilising footing elements adapted to mount one or more monolithic ballast masses; wherein the one or more stabilising footing elements includes a locating region adapted to cooperate with a locating region of the monolithic ballast mass so that the support apparatus in use is weighted down in a selected position on a sea bed. Ballast masses are also described, as are methods for installing the support apparatus and methods for installing power generators on the support apparatus.

FIELD OF THE INVENTION

The present invention relates generally to support apparatus for supporting underwater power generators and apparatus and methods for the deployment of underwater power generators.

BACKGROUND ART

Underwater power generators typically include turbines to convert energy of marine and water currents into usable power, usually electrical power. These underwater power generators are generally difficult to install on valuable sites, partly because the sites are deep below the surface of any body of water. Also, difficulties are encountered due to the water currents at those valuable sites being powerful as well as substantially or generally constantly flowing, even though the water current flows may vary in strength and water current flow direction from time to time.

The forces generated by the water currents are high, increasing the stresses on, and therefore often the weight of, deployment components. This can hamper deployment and installation of the underwater power generator.

Known apparatus for supporting underwater power generators are limited in that they are difficult or complicated to install. Some are held by a complex system of anchors, floating pontoons and are suspended from cables in a pelagic region of the water. Others are mounted on piles driven into the sea bed. Still others involve a complicated system of submerged adjustable decks. In order to install a system which can power a useful area such as a medium-sized coastal town, these systems involve huge expense.

The present inventors have developed a new deployment apparatus and method suitable for use with underwater power generators.

SUMMARY OF INVENTION

In accordance with one aspect of the present invention there is provided a support apparatus for support of an underwater power generator having a power generating portion, the support apparatus including:

-   -   a stand adapted for supporting the power generating portion, the         stand comprising a stabiliser including one or more stabilising         footing elements adapted to mount one or more monolithic ballast         masses;     -   wherein the stabilising footing elements include a locating         assembly having locating region adapted to cooperate with a         locating region on the or each monolithic ballast mass so that         the support apparatus in use is weighted down in a selected         position on a sea bed.

Optionally the locating region on the or each stabilising footing element includes a male portion for interengagement with a cooperating female portion on a ballast mass. Optionally the male portion includes a plinth or ridge or a key extending from and/or along the stabilising footing element. Optionally the plinth or key or ridge extends radially and horizontally along the stabilising footing element so that the ballast mass, when mounted on the stabilising footing element, is disposed in a corresponding radial and horizontal orientation. Optionally there are provided slanted shoulders depending downwardly and outwardly from a side portion of the key so that they may support the location of a ballast mass having cooperating downward sloping underside portions.

Optionally the locating assembly includes a stop so that the ballast masses may locate thereagainst when installed on a respective stabilising footing element. The stop may be a shoulder; optionally it is one or more posts extending upwardly from the or each stabilising footing element. Optionally the posts are arranged in pairs, two per stabilising footing element, generally or substantially on a common pitch circle diameter having its centre disposed on a stand centre.

The or each stabilising footing element may be disposed at a selected distance from the stand centre by a plurality of spokes extending radially from the stand centre. The stabilising footing element may be a plate and may comprise the preferred locating assemblies disposed at various locating assembly regions on the plate distributed from proximal the stand centre to distal the stand centre, at locations near the outer edges of the plate. The stabilising footing element may be an annulus having a main annular body disposed at a distal end of the spokes. Optionally, however, the stabilising footing element includes support foot pads disposed at the distal end of the spokes.

Optionally the spokes are arranged relative to one another so that they are spaced at approximately 120° from one another. One spoke may be longer than another two so that it may provide a stronger support or reaction force in a particular direction. For example, one spoke may be 11 m long while another two may be 8 m long. It will be appreciated that any suitable length can be chosen for the spokes.

Optionally the support foot pads include grip portions for increasing frictional engagement between the sea bed and the stabiliser. Optionally the grip portion includes teeth or ribs in base portions of the support foot pads to bite into the sea bed.

Optionally the support foot pads include a sole portion which has a convex disposition for increasing frictional engagement with the sea bed, and offering more sea bed/teeth engagement.

Optionally the stand includes a pylon portion extending upwardly from the stabiliser. Optionally the pylon is disposed in a central portion of the stand. Optionally the pylon is a hollow cylindrical arrangement suitable for mounting a turbine head thereon. The pylon may also include a rotation mechanism for the turbine. Optionally the pylon is tall enough to support a horizontally-disposed axial turbine having blades approximately 12 m in radial length.

Optionally the turbine head includes a first axial flow blade set arranged on a hub and disposed so that the first blade set is rotated about the hub under the influence of flowing water current from a direction parallel with the sea bed.

Optionally the ballast masses include a recess or keyway as described above. The keyway is set into a base face and has slanted sides. This facilitates easy positioning as will be appreciated when these ballast masses are being located in the locating region while being lowered from a sea surface by long cables.

Optionally the ballast masses include upper faces with a similar profile to that of the locating assembly's male or ridged or plinthed portion. This is so that another ballast mass may be located on top of a first ballast mass in a nesting relationship. Optionally the locating assembly's stops or posts are sufficiently long to be effective in placing a second or third ballast mass, one atop another. Optionally the ballast masses are approximately 200 tonnes in mass and are constructed from steel, concrete or other heavy and dense material and shaped to have negative buoyancy. The ballast masses could be any mass, including 5 tonnes, 10 tonnes, 50 tonnes, 100 tonnes, or other suitable masses.

In accordance with a second aspect, the present invention provides a method of deployment of an underwater power generator, the method including the steps of:

-   -   lowering a stand from a surface of a water body to a sea bed;     -   lowering one or more monolithic ballast masses from the surface         of the water body onto support footing regions of the stand;     -   wherein the lowering step includes the step of locating the one         or more monolithic ballast masses on one or more cooperating         respective locating regions of the support footing regions, the         cooperating locating regions comprising a key adapted to         interengage with a keyway on the monolithic ballast mass.

Preferably, the stand is a support apparatus according to the first aspect of the present invention.

Optionally the method further includes the step of installing a power generating portion onto the stand. In alternative examples, the stand includes a power generating portion installed thereon at the time of lowering.

In accordance with a third aspect, the present invention provides a ballast mass for ballasting an underwater power generator or power generator support, the ballast mass including a locating region in one surface for cooperating with a cooperating locating region in a stand of an underwater power generator.

Optionally the locating region is in the form of a keyway or recess.

Optionally the ballast mass includes a key or ridge or plinth in a second surface for receiving a cooperating keyway or recess in another ballast mass for providing a nesting relationship between ballast masses.

In accordance with a fourth aspect of the present invention there is provided an underwater power generating apparatus including a power generating portion, the power generating apparatus comprising a stand adapted for supporting the power generating portion, the stand comprising a stabiliser including one or more stabilising footing elements adapted to mount one or more ballast masses.

In accordance with a fifth aspect of the present invention there is provided a method of installing an underwater power generator, the method including:

-   -   assembling a power generating head on a support stand;     -   assembling a plurality of ballast masses on locating portions of         the support stand;     -   lowering the support stand, ballast masses and power generating         head to the sea floor.

Preferably, the stand is a support apparatus according to the first aspect of the present invention.

Throughout this specification, unless the context requires otherwise, the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of the invention disclosed in this specification.

In order that the present invention may be more clearly understood, preferred embodiments will be described with reference to the following drawings and examples.

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. 1 is an isometric view of an underwater power generator mounted on a support apparatus in accordance with a preferred embodiment of the present invention;

FIG. 2 is a side elevation view of the underwater power generator of FIG. 1;

FIG. 3 is a front elevation view of the underwater power generator of FIG. 1;

FIG. 4 is an plan schematic view of the support apparatus shown in FIG. 1 with the power generating head of the underwater power generator removed for clarity;

FIG. 5 is a side elevation view of the support apparatus shown in FIG. 1 with the power generator portion removed for clarity;

FIG. 6 is an isometric view of the support apparatus shown in FIG. 1 with the ballast masses and power generator portion removed for clarity;

FIG. 7 is an end elevation view of an optional stabilising footing element in accordance with a portion of a preferred embodiment of the present invention, showing a type of optional cooperating stack of ballast masses stacked on top of the footing; and

FIG. 8 is an end elevation view of another optional stabilising footing element in accordance with a portion of a preferred embodiment of the present invention, showing a type of optional cooperating stack of ballast masses stacked on top of the footing.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS:

Referring to the drawings there is shown an underwater power generator generally indicated at 10, the underwater power generator 10 including a support apparatus 12, the support apparatus including a stand 14. The stand 14 comprises a stabiliser 16 which includes a stabilising footing element 18 in the form of three support foot pads 20, 21, 22. The stabiliser 16 includes spokes 23, 24 and 25 having distal ends 26, 27 and 28 and the support food pads 20, 21, 22 are disposed at the distal ends of the spokes 23, 24 and 25.

The support foot pads 20, 21 and 22 include locating assemblies 30 on each support foot pad. Each locating region 30 is adapted to locate a monolithic ballast mass 50 on a support foot pad 20, the mass of the monolithic ballast mass acting to provide reaction support from marine or water currents for the underwater power generator 10 so that it is weighted down.

The locating regions 30 include a male portion 31 for cooperation or interengagement with a cooperating female portion 51 in the form of a keyway or channel 52 on the monolithic ballast mass 50 when the monolithic ballast mass 50 is installed on the support foot pad 20. The male portion 31 includes a plinth or ridge or key 32 which is disposed centrally on the support foot pad 20 and extends along the support foot pad 20 in a radial direction, parallel each spoke 23, 24, 25. The plinth or ridge or key 32 includes sloping ramps or shoulders 33 to facilitate cooperation and interengagement. It will be appreciated that the monolithic ballast masses 50 will be lowered onto the support foot pads 20 on cables from a height of roughly 30-60 m (at which will be the surface of the body of water). So ramps, sloping shoulders 33 will facilitate the positioning of the or each monolithic ballast mass 50 onto the support foot pads 20.

The locating regions 30 further include stops 34 for locating the monolithic ballast masses 50 thereagainst when installed on a respective stabilising foot pad 20. The stops 34 may be in the form of posts 35 which are disposed extending upwards from the support foot pad 20, in pairs, two per support foot pad 20, each post 35 disposed on a common pitch circle diameter.

Each support foot pad 20 includes a grip region 29 on an undersurface 40 for increasing frictional engagement with the sea bed (not shown). The grip region 29 includes teeth or ridges 41 which may increase biting engagement with the sea bed for improved frictional engagement with the sea bed. The undersurface 40 is convex in shape to improve frictional engagement with the sea bed.

The stand 14 includes a pylon 15 in the form of a hollow cylinder 17 to support a power generating portion 19 in the form of a turbine head 11. The turbine head 11 includes a rotatable mounting portion 13.

The monolithic ballast masses 50 further include an upper profiled face portion 56 similar to that of the support foot pads 20 so that the ballast masses 50 may stack in such a way as to nest with each other when resting on one another, and so that upper masses may be located with the same ease as the lower masses were on the support foot pads 20. The purpose of the key and keyway is also to retain the monolithic ballast masses 50 on the support foot pads and on one another during operation of the power generator 10.

The monolithic ballast masses 50 are approximately 200 tonnes in mass and are constructed from steel, concrete or other heavy and dense material and shaped to have negative buoyancy. However, it should be appreciated that the ballast masses are designed to suit the conditions and local standards and could be any mass, including 5 tonnes, 10 tonnes, 50 tonnes, 100 tonnes, or other suitable masses.

The spokes 23, 24 and 25 extend outwardly from the pylon and are arranged so that they are angularly spaced from one another by approximately 120°. One spoke is slightly longer than the other, as can be seen in FIG. 4 so that that spoke may provide more reaction support for the underwater power generator and may be disposed in a direction of the strongest marine or water current.

One installation technique is to lower the support apparatus 12 (shown in FIG. 5) to the sea bed in a first movement and the power generating head lowered and installed on the support apparatus in a second movement. The ballast masses are then lowered onto the pads 20. In an alternative technique, the stand and power generating head can be lowered together and the ballast masses then applied to the stand foot pads 20. It should be understood that a further option for installing the power generator is to lower the entire apparatus 10, including installed ballast masses, from the surface of the body of water to the sea floor in one lift (or lowering operation). That is, any combination of lifts (lowering operations) which is suitable for the size and mass of the power generation apparatus may be utilised.

It will be appreciated that the ballast masses 50, when being installed, will, using one example installation technique, be lowered on cables (not shown) from above to a position a few metres above the support foot pad 20 and radially a selected distance away from the support foot pad 20. Then, wall 55 of the ballast mass 50 will be brought into abutment with the stop 34, then lowered further so that the key 32 interengages with the keyway 52. Any misalignment of the keyway 52 of the ballast mass 50 with the key 32 will be resolved by the sloping shoulders or ramps 33. The power generating head is then installed on the pylon.

Various kinds of locating regions 30 are contemplated and suitable for use with the present invention. The stabilising foot pads 120, 121 and 122 optionally include a female locating region 130 as shown in FIGS. 7 and 8. The ballast masses 150, 250 in these options include a male portion 151, 251 which cooperates with the female locating region 130 by extending into when resting thereon. The upper surfaces of the ballast masses 151 and 251 are similarly female so as to receive further ballast masses in a stack as shown in FIGS. 7 and 8. The upper surface of a top ballast mass may be flat as shown.

The female locating regions 130 may have sloping shoulders to facilitate positioning. The male locating regions 151 may similarly be cooperatingly tapered.

There may be two male projections 252 and 253 disposed on each side of a female recess 231 as shown in FIG. 8. This may facilitate grip of the ballast masses upon the support foot pads 220 when in position.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. 

1. An underwater power generator support apparatus the underwater power generator having a power generating portion, the support apparatus comprising: a stand adapted for supporting the power generating portion, the stand including a stabilizer including a stabilizer including one or more stabilizing footing elements adapted to mount one or more a monolithic ballast masses; the one or more stabilizing footing elements each including a locating region adapted to cooperate with a locating region on the monolithic ballast mass, the locating region on the one or more stabilizing footing elements including a plinth or ridge, or key extending from and along the one or more stabilizing footing elements for interengagement with a cooperating female portion on the ballast mass, wherein the plinth or ridge or key extends radially and horizontally along the one or more stabilizing footing elements so that the ballast mass, when mounted on the stabilizing footing element, is disposed in a corresponding radial and horizontal orientation so that the support apparatus in use is weighted down in a selected position on a sea bed. 2.-4. (canceled)
 5. The support apparatus in accordance with claim 1 wherein a side portion of the plinth or ridge or key includes slanted shoulders depending downwardly and outwardly therefrom so that the slanted shoulders in use support the location of the ballast mass having cooperating downward sloping underside portions.
 6. The support apparatus in accordance with claim 1 wherein the locating region includes a stop so that the ballast mass may locate thereagainst when installed on the stabilizing footing element.
 7. The support apparatus in accordance with claim 6 wherein the stop is in the form of a shoulder.
 8. The support apparatus in accordance with claim 7 wherein the stop includes one or more posts extending upwardly from the stabilizing footing element.
 9. The support apparatus in accordance with claim 8 wherein the posts are arranged in pairs in which two posts are provided per stabilizing footing element, generally or substantially on a common pitch circle diameter having its center disposed on a stand center.
 10. The support apparatus in accordance with claim 1 wherein a plurality of stacked monolithic ballast masses are disposed one atop another on the one or more stabilizing footing elements.
 11. The support apparatus in accordance with claim 1 wherein the one or more stabilizing footing elements are disposed at a selected distance from the stand center by a plurality of spokes extending radially from the stand center.
 12. The support apparatus in accordance with claim 11 wherein the one or more stabilizing footing elements are in the form of a support foot pad disposed at a distal end of a spoke from the plurality of spokes.
 13. The support apparatus in accordance with claim 11 wherein three spokes from the plurality of spokes are provided and they are arranged so that they are spaced at approximately 120° from one another.
 14. The support apparatus in accordance with claim 11 wherein one spoke from the plurality of spokes is longer than two other spokes from the plurality of spokes so that that the longer spoke may provide a stronger support or reaction force in a selected direction.
 15. The support apparatus in accordance with claim 12 wherein the support foot pad includes grip portions for increasing frictional engagement between the sea bed and the stabilizer.
 16. The support apparatus in accordance with claim 15 wherein the grip portion includes teeth or ribs in a base portion of the support foot pad in use to bite into the sea bed.
 17. The support apparatus in accordance with claim 16 wherein the support foot pad includes a sole portion which has a convex disposition in use for increasing frictional engagement with the sea bed, and offering more engagement between the sea bed and the teeth or ribs.
 18. The support apparatus in accordance with claim 1 wherein the stand includes a pylon portion extending upwardly from the stabilizer, the pylon being disposed in a central portion of the stand and being a hollow cylinder suitable for mounting a turbine head and rotation mechanism thereon.
 19. The support apparatus in accordance with claim 1 further including an underwater power generator mounted to the apparatus. 20.-22. (canceled)
 23. A method of deploying an underwater power generator, the method comprising: lowering a support apparatus in accordance with claim 1 from a surface of a water body to a sea bed; lowering one or more monolithic ballast masses from the surface of the water body onto the support regions of the support apparatus; wherein the lowering step includes the step of locating the one or more monolithic ballast masses on one or more cooperating respective locating regions of the supporting footing regions.
 24. The method in accordance with claim 23 further including installing an underwater power generator onto the support apparatus. 